CN106798565B - X-ray measuring apparatus - Google Patents
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- 238000001514 detection method Methods 0.000 claims abstract description 98
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Abstract
The present invention relates to an X-ray measuring apparatus. A plurality of detection elements (32a) are irradiated with fan-beam-shaped X-rays from an X-ray irradiator (30). The surface density of each detected body part (22a) is calculated based on the attenuation amount of X-rays, which is each detection data detected by each detection element (32 a). In addition, the body thickness of each detected body portion (22a) is calculated based on each detection data. A virtual measurement surface is defined at the center position in the body thickness direction of each body part (22a) based on the calculated body thickness. The area density of each sample part (22a) is multiplied by the area of each virtual measurement surface defined in each sample part (22a), and a plurality of element unit masses representing the mass of each sample part (22a) are calculated. The mass of the object (22) is calculated by summing the unit masses of the plurality of elements.
Description
Technical Field
The present invention relates to an X-ray measurement apparatus, and more particularly to a technique for calculating the mass of an object.
Background
Conventionally, an X-ray measurement apparatus is used in a medical institution or the like. In an X-ray measurement apparatus, an X-ray is irradiated to a subject, and various measurements are performed based on the attenuation amount of the X-ray transmitted through the subject. Conventionally, although an X-ray measurement apparatus generally measures a bone salt amount, a body fat percentage, and the like, a technique for measuring a mass of a subject in the X-ray measurement apparatus has been proposed in recent years. For example, japanese patent application laid-open No. 2013-532823 discloses a technique for determining the weight of a subject using an X-ray measuring device.
As one method for measuring the mass of an object in an X-ray measurement apparatus, the following method is mentioned. Fig. 5 is a diagram for explaining a conventional mass measurement method in an X-ray measurement apparatus. As shown in fig. 5, the subject 5 is disposed between the X-ray light source 1 and the plurality of detection elements 3. The X-rays emitted from the X-ray source are fan beams, and are emitted from the X-ray source 1 so as to extend in the X-axis direction. The irradiation range of the X-ray irradiated from the X-ray light source is indicated by a 1-dot chain line.
The plurality of detecting elements 3 are arranged in the expanding direction of the fan beam. The X-ray transmission regions detected by the respective detection elements 3 are indicated by 2-dot chain lines. Each transmission region includes a subject portion 5a which is a part of the subject 5. For example, the transmission region corresponding to the detection element 3a includes the subject portion 5a indicated by oblique lines. In addition, since the detection element 3a (and the X-ray light source 1) scans in the y-axis direction, the portion 5a of the object corresponding to the detection element 3a changes in timing.
If the X-ray light source 1 and the plurality of detection elements 3 scan in the y-axis direction, the fan-beam-shaped X-rays scan in the y-axis direction, and as a result, a detection data group consisting of a plurality of detection data arranged in 2 dimensions is obtained. Fig. 6 is a conceptual diagram of the obtained 2-dimensional detection data group 9.
The area density (mass per unit area) of each portion to be detected 5a is obtained from the detection data detected by each detection element 3. Specifically, the area density of the corresponding object 5a is obtained from each detection data 9a in the detection data group 9.
The element unit mass of each piece of detection data 9a is calculated by multiplying the unit area of the detected body portion 5a corresponding to each piece of detection data 9a by the area density of each detected body portion 5a calculated from each piece of detection data 9 a. The element unit mass is the mass of each of the test object portions 5 a. A unit area of each of the test object portions 5a is defined in each of the test object portions 5a, and is set as an area of a surface (hereinafter referred to as a "virtual measurement surface") provided in parallel with the detection element surface 3 b. That is, the unit area of each of the objects 5a indicates the area of the horizontal cross section (cross section of a plane parallel to the detection element plane 3 b) of each of the object parts 5 a.
The virtual measurement surface 7 (see fig. 5) is defined for each subject 5 a. Let l be the distance between the X-ray source 1 and the virtual measurement surface 71Let the distance between the X-ray light source 1 and the detection element surface 3b be l2D represents the length of each detection element 3 in the fan beam expansion direction (x-axis direction)xThen, the length of the virtual measurement surface 7 in the x-axis direction (Δ x in fig. 5) is obtained by the following formula)。
[ mathematical formula 1]
The length of the virtual measurement surface 7 in the y-axis direction is a distance after the X-axis light source 1 and the plurality of detection elements 3 move in the y-axis direction before detection data is obtained in all the detection elements 3, and is defined as Δ y. Then, the area of the virtual measurement surface 7 is obtained by the following equation.
[ mathematical formula 2]
The area of each virtual measurement surface 7 thus obtained is a unit area related to each object portion 5 a.
The mass (element unit mass) of each detected body portion 5a is obtained by the multiplication processing of the area density and the unit area of each detected body 5a calculated as described above, and the mass of the detected body 5 is obtained by summing up a plurality of element unit masses.
As described above, the unit area of each object portion 5a, that is, the area of the virtual measurement surface 7 is an important parameter that directly affects the calculated mass of the object 5. However, in the related art, the area of the virtual measurement surface 7 is set equally in each of the subjects 5 a. That is, the positions of the virtual measurement surfaces 7 of the respective subjects 5a are defined at uniform distances from the X-ray light source 1.
When the beam shape of the X-ray is a fan shape like a fan beam shape, the calculation result has an error due to the positions of the virtual measurement surfaces 7 being defined uniformly. As can be seen from fig. 5, when a fan-shaped X-ray beam is used, the horizontal cross-sectional area of each object portion 5a becomes smaller as it is closer to the X-ray light source 1 and becomes larger as it is farther from the X-ray light source 1.
Therefore, it is necessary to appropriately define the position of the virtual measurement surface in the body thickness direction. Specifically, the virtual measurement surface 7 should be set at a position away from the X-ray light source 1 for a portion with a large body thickness (i.e., the area of the virtual measurement surface 7 should be made larger), and the virtual measurement surface 7 should be set at a position close to the X-ray light source 1 for a portion with a small body thickness (i.e., the area of the virtual measurement surface 7 should be made smaller). Conversely, if the virtual measurement surfaces 7 are defined at equal areas on the respective virtual measurement surfaces 7, that is, at equal positions from the X-ray irradiator, there is a problem that the mass is excessively evaluated (excessively calculated) for the thin portion and excessively evaluated (excessively calculated) for the thick portion.
Disclosure of Invention
The purpose of the present invention is to further improve the measurement accuracy of the mass of an object to be measured in an X-ray measurement device.
An X-ray measuring apparatus according to the present invention includes: an X-ray irradiator that irradiates an object with X-rays having a fan-shaped beam shape; an X-ray detection element that detects the X-ray transmitted through the subject and outputs detection data; and a mass calculation unit for calculating an element unit mass by multiplying the area density of a portion of the subject included in the X-ray transmission region detected by the X-ray detection element, which is specified based on the detection data output from the X-ray detection element, by the unit area calculated based on the detection data, and calculating the mass of the subject based on the element unit mass.
Preferably, a plurality of the X-ray detection elements are provided, the plurality of the X-ray detection elements output a plurality of the detection data, and the mass calculation unit calculates the element unit mass for each of the X-ray detection elements and calculates the mass of the object as a sum of the plurality of element unit masses calculated for the plurality of the X-ray detection elements. Preferably, the unit area is calculated based on a body thickness of the subject portion, and the body thickness of the subject portion is calculated based on detection data output from the X-ray detection element.
According to the above configuration, the unit area of each of the test object portions is determined based on the detection data corresponding to each of the test object portions. For example, if the radiation absorption coefficient of the object is known, the body thickness of the object portion can be calculated from the detection data, that is, the attenuation amount of the X-ray. The unit area of each of the test object parts can be set based on the body thickness of each of the test object parts calculated in this manner. This can solve the conventional problem that the quality is excessively evaluated for a portion having a small thickness and is excessively evaluated for a portion having a large thickness.
Preferably, the unit area is defined at a center position in a body thickness direction of the subject portion, and is calculated as an area of a virtual measurement surface which is a surface parallel to a detection surface of the X-ray detection element.
Since the X-rays irradiated from the X-ray irradiator have a fan-shaped beam shape, that is, a shape expanding in the forward direction, the area of the virtual measurement surface defined in the object portion becomes smaller as it approaches the X-ray irradiator and becomes larger as it moves away from the X-ray irradiator. That is, the area differs depending on the defined position of the virtual measurement surface. Here, the area density calculated in each X-ray detection element is the area density calculated from the X-rays transmitted through the entire part of the object corresponding to each X-ray detection element. Therefore, the unit area is preferably an average area of the areas of the virtual measurement surfaces defined in the object portion. The area of the virtual measurement surface defined at the center position in the body thickness direction of the detected body portion becomes the average area. By setting the virtual measurement area at the center position in the body thickness direction of the detected body portion, the mass of the detected body can be calculated with higher accuracy.
Preferably, the X-ray detector further includes an alarm unit configured to output an alarm when the body thickness of the portion to be detected calculated based on the detection data output from the X-ray detector is equal to or greater than a predetermined value. It is impossible to appropriately perform X-ray measurement on a subject having a too thick body. Therefore, when the body thickness of the subject portion is equal to or greater than a predetermined value (the predetermined value is determined based on the body thickness that can be measured by X-ray appropriately), an alarm is output, which can suggest to the measurer that the obtained data is possibly incorrect.
Further, the X-ray measurement program of the present invention causes a computer to function as a mass calculation means for calculating an element unit mass by multiplying a unit area calculated from detection data by a surface density of a portion of an object to be detected included in an X-ray transmission region detected by an X-ray detection element, which is specified from the detection data output from the X-ray detection element that detects an X-ray having a fan-shaped beam shape and transmitted through the object, and calculating the mass of the object based on the element unit mass.
Drawings
Fig. 1 is an external perspective view of an X-ray irradiation detector.
Fig. 2 is a diagram showing a state in which an imaging table and a subject are installed in an X-ray irradiation detection apparatus.
Fig. 3 is a functional block diagram of the X-ray measurement device according to the present embodiment.
Fig. 4 is a diagram for explaining the mass calculation method according to the present embodiment.
Fig. 5 is a diagram for explaining a conventional quality calculation method.
Fig. 6 is a conceptual diagram showing a plurality of detection data arranged in 2 dimensions.
Detailed Description
The X-ray measuring apparatus of the present invention will be described below. An X-ray measuring apparatus according to the present invention is used for medical purposes, for example, and measures the mass of a subject based on detection data obtained by irradiating the subject with X-rays and detecting the X-rays transmitted through the subject. In addition, in the X-ray measurement device, in addition to measuring the mass of the subject, the bone mineral mass, bone density, body fat percentage, and the like of the subject can be measured based on the detection data.
Fig. 1 is an external perspective view of an X-ray irradiation detector 10 included in an X-ray measuring apparatus according to the present invention. Fig. 2 is a side view showing a state in which the X-ray irradiation detector 10 is provided with an imaging table and a subject. In fig. 1 and 2, the X-ray irradiation detector 10 has a width direction (left-right direction) as an X-axis, a length direction (depth or front-back direction) as a y-axis, and a height direction as a z-axis.
The X-ray irradiation detector 10 includes: a base 12 having a substantially コ -shaped (U-shaped) side view and extending in a horizontal direction; an arm portion 14 extending horizontally above the base portion 12; and a wall portion 16 extending upward from one end of the base portion 12 and supporting the arm portion 14 in a cantilever manner.
As shown in fig. 2, the X-ray irradiation detector 10 is used together with a photographing table (filter table) 18. The X-ray irradiation detector 10 is movable by a rolling wheel (Caster), and when the X-ray irradiation detector 10 is used, the position of the X-ray irradiation detector 10 is adjusted so that a top plate 20 of the imaging table 18 is located between the base 12 and the arm 14. In addition, the subject 22 is placed on the top surface of the top plate 20 of the imaging table, and the subject 22 is disposed between the base 12 and the arm 14.
An X-ray irradiation detector top plate 24 (see fig. 1) made of a material that can transmit X-rays is disposed on the upper surface of the base 12. In a space below the X-ray irradiation detector top plate 24, an X-ray irradiator that irradiates X-rays scans in the depth direction (y-axis direction). X-rays are irradiated upward from an X-ray irradiator during scanning. The X-rays irradiated from the X-ray irradiator and passed through the object to be detected are detected by an X-ray detector provided in the arm portion 14 and scanning in synchronization with the X-ray irradiator.
Further, a housing case 26 is attached to the front surface of the wall portion 16, and a correcting substance mainly for measuring bone density is housed in the housing case 26.
Fig. 3 is a functional block diagram of an X-ray measuring apparatus according to the present invention. The X-ray measurement device of the present embodiment includes an X-ray irradiation detector 10 and a measurement terminal 40.
The X-ray irradiator 30 irradiates a fan-shaped (shape spreading in the traveling direction) X-ray toward the subject. In the present embodiment, the X-ray irradiation detector 10 irradiates X-rays having a fan beam shape extending in the left-right direction (X-axis direction). The X-ray irradiation detector 10 of the present embodiment can irradiate the object with high-energy X-rays and low-energy X-rays. Thus, the body fat percentage, the bone salt content, and the like can be calculated by the DEXA (Dual-Energy X-ray absorption measurement) method based on the ratio of the attenuation amounts of the two X-rays in the measurement terminal 40 described later.
The X-ray detector 32 detects X-rays irradiated from the X-ray irradiator 30 and transmitted through the object 22. The X-ray detector 32 includes a plurality of detection elements arranged in a direction corresponding to the shape of the X-rays irradiated from the X-ray irradiator 30. In the present embodiment, since the X-ray irradiator 30 irradiates X-rays having a fan beam shape extending in the left-right direction, the X-ray detector 32 includes a plurality of detection elements arranged in a row in the left-right direction. Alternatively, an X-ray detector in which a plurality of detection elements are arranged in a 2-dimensional direction in the left-right direction and the depth direction may be used instead of the above-described X-ray detector.
The scanning unit 34 scans the X-ray irradiator 30 and the X-ray detector 32 in the depth direction. Thereby, the fan-beam-shaped X-ray is scanned in the depth direction. Each of the detection elements included in the X-ray detector 32 detects X-rays while scanning itself, and transmits each of detection data obtained by the detected X-rays to the measurement terminal 40 via the control unit 36 described later. Thus, the measurement terminal 40 obtains a detection data group including a plurality of detection data arranged in 2 dimensions (see fig. 6).
The control unit 36 is configured by, for example, a microprocessor or the like, and controls each unit of the X-ray irradiation detector 10 according to a program stored in a storage unit (not shown) provided in the X-ray irradiation detector 10. The control unit 36 transmits an X-ray irradiation start instruction and an X-ray irradiation stop instruction to the X-ray irradiation unit 30 to start and stop the X-ray irradiation by the X-ray irradiation unit 30, or transmits a scan instruction to the scanning unit 34 to scan the X-ray irradiation unit 30 and the X-ray detector 32 by the scanning unit 34.
The measurement terminal 40 is a terminal used by a measurement person such as a doctor or a nurse, and is, for example, a personal computer. The measurement terminal 40 is connected to the X-ray irradiation detector 10 in a wired or wireless communication manner, and is disposed in a room different from the X-ray irradiation detector 10 in order to prevent the measurement subject from being irradiated. The measurement terminal 40 includes a calculation unit 42 and a storage unit 44.
The calculation unit 42 is realized by a calculation device such as a CPU. The calculation unit 42 calculates the mass of the object 22 based on the detection data group transmitted from the X-ray irradiation detector 10 (control unit 36). In the present embodiment, the calculation unit 42 particularly calculates the mass of the subject excluding the soft tissue of the bone. The calculation unit 42 has a function Of specifying a Region Of the subject (ROI: Region Of Interest) Of which the quality is to be calculated. The ROI may be designated manually or by an instruction from the measurer (not shown) inputted from an input unit (not shown) of the measurement terminal 40, or may be automatically set based on the detection data from the X-ray irradiation detector 10. The calculation unit 42 calculates the bone salinity, bone density, body fat percentage, and the like of the subject by using the DEXA method from the detection data group relating to the high-energy X-ray and the low-energy X-ray. The mass calculation process of the calculation section 42 is described in detail later.
The storage unit 44 is configured by a hard disk, a ROM, a RAM, or the like, and stores a detection data group transmitted from the X-ray irradiation detector 10, a program for operating each unit of the measurement terminal 40, and the like.
The measurement terminal 40 further includes: an image forming unit for forming an image such as an X-ray image; a display unit including a liquid crystal panel or the like; a CPU or the like, which controls each unit of the measurement terminal 40 according to a program stored in the storage unit 44; and an input unit configured by a mouse, a keyboard, or the like, for inputting an instruction of the measurer to the measurement terminal 40.
The following describes a calculation process of the calculation unit 42 for calculating the mass of the subject.
Fig. 4 is a side conceptual view of the X-ray irradiation detector 10 viewed from the near side direction, and shows the positional relationship among the X-ray irradiator 30, the X-ray detector 32, and the object 22.
As described above, the X-ray detector 32 has the plurality of detection elements 32a arranged in the left-right direction (X-axis direction). The plurality of detecting elements 32a are rectangular or square in plan view, and have uniform lengths in the left-right direction.
The X-rays having a fan beam shape spreading in the left-right direction are emitted upward from a point light source 30a of the X-ray irradiator 30. In fig. 4, the irradiation range of the X-ray to be irradiated is indicated by a 1-dot chain line. A measurement site (hereinafter, collectively referred to as "subject") which is the subject 22 or a part thereof mounted on the top plate 20 of the imaging table is disposed in the irradiation range. For convenience, the cross section of the subject 22 is shown by a semicircle in fig. 4.
As shown in fig. 4, the X-rays irradiated from the point light source 30a are transmitted through the subject 22 and detected by the plurality of detection elements 32 a. In fig. 4, the X-ray transmission regions detected by the respective detection elements 32a are shown by 2-dot chain lines. A part of the object 22 included in each transmission region is an object portion 22 a. Each of the detection elements 32a detects the X-rays transmitted through the corresponding object portion 22a and attenuated, and outputs a plurality of detection data corresponding to each of the object portions 22 a.
Also in the present embodiment, as in the conventional case, the mass (element unit mass) of each sample portion 22a is calculated by multiplying the area density of each sample portion 22a by the unit area corresponding to each sample portion 22a, and the mass of each sample 22 is calculated by summing up the element unit masses corresponding to a plurality of detection data. However, in the present embodiment, the method of setting the unit area is different from the conventional method. The following description is made in detail.
First, a method of calculating the areal density of each of the test body portions 22a will be described. It is known that the attenuation of X-rays transmitted through soft tissue without a bone can be expressed by the following equation.
[ mathematical formula 3]
RH＝μHS·XS… … (equation 3)
In formula 3, RHIs the attenuation amount, mu, of high-energy X-rays when the X-rays transmit through the subjectHSIs the radiation absorption coefficient (unit is "1/cm") of soft tissue, XSIs the thickness (in "cm") of the object 22. In addition, from the viewpoint of simplifying the calculation process, the mass calculation is performed using high-energy X-rays. In detail, the radiation absorption coefficient μ for high-energy X-rays is knownHSApproximately the same in the fat portion and the fat-free portion. Thus, by using high-energy X-rays, μ can be adjustedHSDefined as fat and soft tissue mass coexisting with the exception of fatThe radiation absorption coefficient of (a), whereby the calculation is simplified.
Here, the radiation absorption coefficient μ is obtained by multiplying the density of the object 22 by the mass absorption coefficientHSSo it is expressed by the following formula.
[ mathematical formula 4]
μHS＝ρ·μ’HS… … (equation 4)
In equation 4, ρ is the density of the object 22 (in "g/cm3”)，μ’HSIs the mass absorption coefficient (in "cm2In terms of,/g "). Further, the mass absorption coefficient μ 'is known'HSThe fat portion and the fat-free portion are also approximately the same.
The thickness X of the test object is obtained by dividing the area density (mass per unit area) of the test object 22 by the density of the test object 22SAnd is therefore represented by the following formula.
[ math figure 5]
In equation 5, σ is the areal density σ s (unit is "g/cm2”)。
If equations 4 and 5 are substituted into equation 3, the following equations are obtained.
[ mathematical formula 6]
RH＝μ’HSσ … … (equation 6)
Next, a method of setting the unit area of each sample portion 22a will be described. In the present embodiment, the unit area of each of the object parts 22a is calculated from the detection data corresponding to each of the object parts 22 a. Specifically, the body thickness of each detected body portion 22a is calculated from the detection data corresponding to each detected body portion 22a, and each unit area is set based on the body thickness. The following description will be made in detail.
The following formula is obtained from formula 5 and formula 6.
[ math figure 7]
The density ρ of the soft tissue is a known value (approximately the same as water) and the mass absorption coefficient μ 'as described above'HSIs a known value, so equation 7 represents the attenuation amount (R) according to the high-energy X-rayH) The body thickness was determined. Specifically, the body thickness of each object portion 22a is determined from the attenuation amount of the high-energy X-ray detected for each object portion 22 a.
If the body thickness of each detected body portion 22a is found, the unit area corresponding to each detected body portion 22a can be set according to the body thickness. That is, unlike the conventional art, different unit areas corresponding to the body thickness of each subject 22a can be set. In the present embodiment, the position of the virtual measurement surface 50 defined in each of the test object parts 22a is set according to the body thickness, and the unit area (the area of the virtual measurement surface) corresponding to each of the test object parts 22a is appropriately set.
Let L be the distance between the point light source 30a and the mounting surface 20a of the table top 201L represents the distance between the mounting surface 20a and the virtual measurement surface 502L is a distance between the point light source 30a and the detection element surface 32b of the X-ray detector 323D represents the length of each detection element 32a in the fan beam expansion direction (x-axis direction)xThen, the length of the virtual measurement surface 50 in the x-axis direction (Δ x in fig. 4) is obtained by the following equation.
In the present embodiment, each virtual measurement surface 50 for each object portion 22a is set at the center position in the body thickness direction of each object portion 22 a. Since the body thickness of each test object portion 22a is calculated by the formula 7, the distance between the placement surface 20a and each virtual measurement surface 50 set at the center position in the body thickness direction of each test object portion 22a is expressed by the following formula:
[ mathematical formula 9]
Δ x obtained by substituting equation 9 into equation 8 is defined as the length of the virtual measurement surface 50 in the x-axis direction.
The length Δ y in the y-axis direction of each virtual measurement surface 50 is the same as that of the conventional art, and is the distance that the point light source 30a (X-ray irradiator 30) and the X-ray detector 32 move in the y-axis direction before detection data is obtained in all the detection elements 32 a. Then, the calculated Δ x and Δ y are multiplied to calculate the area of each virtual measurement surface 50, that is, the unit area of each object 22 a.
As shown in fig. 4, since the X-ray emitted from the point light source 30a has a beam shape spreading in the left-right direction, the area of the virtual measurement surface 50 defined in the object portion 22a (specifically, the length of the virtual measurement surface 50 in the left-right direction) becomes smaller as it approaches the point light source 30a and larger as it moves away from the point light source 30 a. Each of the areal densities calculated for each of the object parts 22a is calculated from the X-rays transmitted through the entirety of each of the object parts 22 a. Therefore, it is preferable to set the average length of the lengths in the left-right direction of the test object portion 22a different at each position in the up-down direction as the length in the left-right direction of the virtual measurement surface 50. The average length indicating the length of each detected body portion 22a in the left-right direction is the center position of each detected body portion 22a in the body thickness direction. Therefore, by setting the virtual measurement surface at the center position in the body thickness direction of each detected part 22a, the mass of the detected body can be calculated with higher accuracy and lower cost.
The body thickness of each detected part 22a is calculated from each detection data (attenuation amount of high-energy X-ray) according to the above formula 7. The calculated body thickness of each detected part 22a (i.e., the body thickness of the detected body 22) can be used for various processes. For example, in view of the fact that X-ray measurement cannot be performed appropriately for a subject having a too large body thickness (for example, a subject having a body thickness of 20cm or more), when the body thickness calculated by the above equation 7 exceeds a predetermined value, an alarm can be output to the measurer. The measurer who has confirmed the alarm may not be able to grasp the detection data obtained by scanning the X-ray on the subject. This alarm is given by displaying an error on a display unit of the measurement terminal 40 in accordance with an instruction from a control unit (not shown) of the measurement terminal 40. Alternatively, in addition to this or instead of this, the control unit of the measurement terminal 40 may emit sound or light in the measurement terminal 40 or the X-ray irradiation detector 10.
This alarm may be output at the time of analysis of the detection data after the X-ray scanning of the object 22 is performed, or may be output during the X-ray scanning if the body thickness of each detected part 22a is calculated in real time (that is, during the X-ray scanning). When an alarm is output during the scanning of X-rays, the irradiation of X-rays from the X-ray irradiator 30 is immediately stopped while the alarm is output, from the viewpoint of avoiding meaningless irradiation of the object 22.
As described above, according to the present embodiment, an appropriate unit area corresponding to the body thickness of each detected body portion 22a is set for each detected body portion. Thus, as compared with the case where the mass of the subject is calculated by setting the unit area of each subject portion uniformly, the mass (element unit mass) of each subject portion 22a can be calculated more accurately from the body thickness, and the mass of the entire subject 22 can be calculated more accurately.
While the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, although the present embodiment uses a fan beam-shaped X-ray beam, the present invention can be suitably applied to the case of calculating the mass using a beam-shaped X-ray beam that expands in the traveling direction, such as a cone beam or a pen beam. In the present embodiment, since a fan beam-shaped X-ray (i.e., a beam that spreads in one direction) is used, the length of the virtual measurement surface is corrected only in the X-axis direction, and when a beam that spreads in 2 directions such as a cone beam is used, the length of the virtual measurement surface is corrected in 2 directions of the X-axis and the y-axis. In this case, the length correction in the y-axis direction is realized by the same processing as described above.
In an X-ray measuring apparatus using a pencil beam-shaped X-ray, an X-ray irradiator and an X-ray detector sequentially scan (zigzag scan) in a y-axis direction (depth direction) in respective lines arranged in an X-axis direction (left-right direction) of an irradiation region. In this case, since the pen beam has a slight beam spread in the x-axis direction, the length of the virtual measurement surface is corrected in the x-axis direction by applying the present invention.
In the present embodiment, since the mass (element unit mass) of each of the test object parts 22a is individually calculated, the mass of an arbitrary region (part) of the test object can be calculated. For example, the mass of the partial detection object specified as the ROI can be calculated by summing the element unit masses of the object parts 22a included in the ROI specified by the measurer.
In the present embodiment, the X-ray irradiation detector 10 and the measurement terminal 40 are separate bodies, but a system in which the functions of the calculation unit 42 and the storage unit 44 of the measurement terminal 40 are incorporated in the X-ray irradiation detector 10 may be adopted.
Claims (4)
1. An X-ray measuring apparatus is characterized in that,
the X-ray measurement device is provided with:
an X-ray irradiator that irradiates an object with X-rays having a fan-shaped beam shape;
an X-ray detection element that detects the X-ray transmitted through the subject and outputs detection data; and
a mass calculation unit for calculating an element unit mass by multiplying the area density of a portion of the subject included in the X-ray transmission region detected by the X-ray detection element, which is specified based on the detection data output from the X-ray detection element, by the unit area calculated based on the detection data, and calculating the mass of the subject based on the element unit mass,
wherein the unit area is calculated based on a body thickness of the subject portion, and the body thickness of the subject portion is calculated based on detection data output from the X-ray detection element.
2. The X-ray measuring apparatus according to claim 1,
a plurality of X-ray detecting elements for outputting a plurality of detection data are provided,
the mass calculation unit calculates the element unit mass for each of the X-ray detection elements, and calculates the mass of the object as the sum of the plurality of element unit masses calculated for the plurality of X-ray detection elements.
3. The X-ray measuring apparatus according to claim 1,
the unit area is defined at the center position in the body thickness direction of the subject portion, and is calculated as the area of a virtual measurement surface that is a surface parallel to the detection surface of the X-ray detection element.
4. The X-ray measuring apparatus according to any one of claims 1 to 3,
the X-ray measurement device further includes: and an alarm unit that outputs an alarm when the body thickness of the portion to be detected calculated based on the detection data output from the X-ray detection element is equal to or greater than a predetermined value.
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| JP2015230893A JP6661344B2 (en) | 2015-11-26 | 2015-11-26 | X-ray measurement device |
| JP2015-230893 | 2015-11-26 |
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| WO2021153592A1 (en) * | 2020-01-29 | 2021-08-05 | キヤノン株式会社 | Image processing device, radiography device, image processing method, and program |
| CN115388791B (en) * | 2022-10-31 | 2023-01-24 | 临沂紫晶光电有限公司 | Lens thickness shape detection device and detection method |
| WO2024103240A1 (en) * | 2022-11-15 | 2024-05-23 | 宁德时代新能源科技股份有限公司 | Pole piece quality test method and apparatus, coating method and apparatus, and device, system and medium |
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|---|---|---|---|---|
| US3983368A (en) * | 1973-03-19 | 1976-09-28 | Commissariat A L'energie Atomique | Apparatus for non-traumatic determination of the mass and the position of the center of gravity of a body |
| US6081582A (en) * | 1992-09-14 | 2000-06-27 | Lunar Corporation | Transverse scanning densitometer |
| EP1044649A1 (en) * | 1999-04-15 | 2000-10-18 | Hologic, Inc. | Determining body composition using fan beam dual-energy x-ray absorptiometry |
| US6217214B1 (en) * | 1993-11-22 | 2001-04-17 | Hologic, Inc. | X-ray bone densitometry apparatus |
| US20050089135A1 (en) * | 2003-10-27 | 2005-04-28 | Toth Thomas L. | System and method of x-ray flux management control |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3983368A (en) * | 1973-03-19 | 1976-09-28 | Commissariat A L'energie Atomique | Apparatus for non-traumatic determination of the mass and the position of the center of gravity of a body |
| US6081582A (en) * | 1992-09-14 | 2000-06-27 | Lunar Corporation | Transverse scanning densitometer |
| US6217214B1 (en) * | 1993-11-22 | 2001-04-17 | Hologic, Inc. | X-ray bone densitometry apparatus |
| EP1044649A1 (en) * | 1999-04-15 | 2000-10-18 | Hologic, Inc. | Determining body composition using fan beam dual-energy x-ray absorptiometry |
| US20050089135A1 (en) * | 2003-10-27 | 2005-04-28 | Toth Thomas L. | System and method of x-ray flux management control |
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| JP2017093911A (en) | 2017-06-01 |
| CN106798565A (en) | 2017-06-06 |
| JP6661344B2 (en) | 2020-03-11 |
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